Justification:
Listed as Vulnerable as the species is suspected to have undergone a population decline of ≥30% over a period of 24 years (three generations), primarily due to continuing decline in area, extent and quality of habitat, in addition to exploitation through unsustainable hunting pressure. These causes have not ceased, and will to a large extent not be easily reversible.

The range of E. rubriventer extends from northern Madagascar’s Tsaratanana Massif south along the thin strip of east coast rain forest to the Pic d'Ivobe and the Manampatrana River (Irwin et al. 2005), although at one time it ranged further south. It does not occur on the Masoala Peninsula. Ranges from 70-2,400 m. Over its relatively large range the Red-bellied Lemur is sympatric with four other Eulemur species: E. albifrons in the northern part, E. fulvus toward the middle, and E. rufifrons and E. cinereiceps in the southern part. However, this species appears to be thinly distributed and restricted to intact forests, and is usually considerably more rare than other sympatric Eulemur.

Eulemur rubriventer has an estimated density of 5.46 individuals/km2 with a total estimated population of 1,802 within Ranomafana National Park (Wright et al. 2012). Individuals are only found at higher altitudes. Densities vary across regions, and so cannot be assumed to be as high in other areas as in Ranomafana National Park. Overall, population numbers are in decline due to habitat loss and hunting.

This species appears to be restricted mainly to primary forest habitats, as high as 2,400 m on the Tsaratanana Massif, as well as primary and secondary coastal rainforest. Its activity pattern is characterized as cathemeral, and group size varies from two to 10 individuals, the typical group containing an adult pair and their offspring. Home range size has been estimated at 12-15 ha. Young are born in September and October, after a gestation period of 123–127 days. One infant is usually born per year to each group and mortality is approximately 50%. Weaning occurs at 6–7 months. They are very specialized frugivores, and an important seed disperser (Mittermeier et al. 2008, and references therein).

This species is listed on Appendix I of CITES. Though relatively widespread this species appears to be everywhere uncommon, and has declined drastically in number in recent years. It is known to occur in five national parks (Andringitra, Mantadia, Marojejy, Ranomafana, and Zahamena), two strict nature reserves (Tsaratanana and Zahamena), and six special reserves (Ambatovaky, Analamazaotra, Anjanaharibe-Sud, Mangerivola, Marotandrano, and Pic d' Ivohibe) (Nicoll and Langrand 1989, Schmid and Smolker 1998). As of 2009, there were approximately 165 individuals reported in zoological collections worldwide (ISIS 2009).